Add report fragments and export manifest

docs/ARCHITECTURE-BLUEPRINT.md

@@ -653,6 +653,18 @@ building complex runtime code.
 - `reported_metadata`
 - `certification_boundary`
 
+### `ExportManifest`
+
+- `export_type`
+- `source_package_ref`
+- `source_lock_ref`
+- `summary`
+- `policy_summary`
+- `mapping_summary`
+- `report_fragments`
+- `counts`
+- `certification_boundary`
+
 ## Result Vocabulary
 
 The evidence model should allow these statuses:
@@ -740,9 +752,11 @@ runs/<run-id>/
     mappings.json
   reports/
     report.md
+    fragments.json
     assessment-package.json
     submission-package.json
   exports/
+    export-manifest.json
 ```
 
 ## Container And Service Model
@@ -836,6 +850,8 @@ hooks for runners and normalizers.
 6. Add container design after the CLI baseline is stable.
 7. Add optional service API around the CLI job model.
 8. Add OSCAL export and procedural evidence-pack support after the internal
-   evidence model proves itself with executable extensions.
+   evidence model proves itself with executable extensions. The first generic
+   export is `exports/export-manifest.json`; authority-specific interchange
+   remains extension-owned until the internal model is stable.
 
 The first extension SDK contract is documented in `docs/EXTENSION-SDK.md`.